The role of bacterial adherence in the pathogenesis of urinary trace infections is not clear but binding of specific strains to the urogenital epithelium of susceptible individuals appears to be one of the factors associated with successful microbial invasion of the urinary tract. This proposal is designed to assess changes in adherence associated with bacterial virulence in and host susceptibility to urinary infections. The pathogenicity and site of origin of E. coli will be correlated with their adherence to epithelial cells from the genitourinary tract of patients with frequent urinary tract infections and controls. Adherence will be determined by utilizing radioisotopically labeled bacteria and vacuum filtration with polycarbonate membranes. E. coli which frequently are associated with urinary infection will be obtained from the kidney pelvis, bladder, vaginal and anal mucosa. Strains transiently present in anal flora will also be utilized. Adherence to epithelial cells from washed bladder and midstream urine specimens as well as the vaginal mucosa from women with recurrent urinary infection and controls will be determined. A second major objective is to further characterize the mechanisms of bacterial and epithelial cell binding. These studies will focus on the effect of pH temperature, time, concentration and cations on adherence. Attempts will be made to define bacterial and epithelial cell receptors using enzyme treatment, periodate oxidation, lectins and carbohydrate blocking agents. We will also attempt to block adherence by treating bacteria with antisera to pili, and O and K antigens. The role of electrostatic charge on the surface of bacteria will be examined by altering the surface changes and manipulating the concentration of ions in the medium during adherence.